A crawler-type or tracked vehicle is normally supported and propelled by an undercarriage assembly having an endless track entrained about a drive roller or sprocket, a front idler roller, a rear idler roller, and a series of track rollers. The drive roller or sprocket is driven by an engine of the work vehicle which, in turn, causes the endless track to be advanced around each of the front and rear idler rollers as well as the track rollers to advance the work vehicle.
For an endless track to function properly, it must be properly tensioned around the several rollers, and the several rollers must be properly maintained to ensure they roll with the least amount of friction while supporting the weight of the vehicle. Tracked vehicles are normally considerably heavy. As a result, the rollers are prone to generate substantial frictional heat as they are made to roll as the tracked vehicle advances. Excessive frictional heat in the rollers can lead to roller failure and expensive and time-consuming repair costs. Limiting frictional heat in rollers is accomplished with a lubricating oil, which is applied to and maintained by lubricating oil reservoirs formed in the rollers. The lubricating oil must be periodically replenished, and periodically replaced to ensure the oil functions properly, namely, that it reduces roller friction and draws and dissipates heat away from the rollers. Contaminated or dirty oil and reduced oil levels impede the ability of the oil to reduce friction and dissipate heat. Accordingly, proper oil maintenance in rollers is essential for proper operation of the tracked vehicle and to limit unnecessary and time-consuming roller repairs.
The rollers of tracked vehicles are often fashioned with caps that close the open ends of the rollers that lead to the lubricating oil reservoirs. These caps are removably coupled to the rollers, such as with bolts, and provide trained workers to convenient access to the lubricating oil reservoirs for facilitating the replenishment and replacement of the lubricating oil in the lubricating reservoirs. It is essential that a reliable and durable fluid-impervious seal be formed between the caps and the open ends of the rollers to prevent unnecessary leaking past the applied caps. This fluid impervious seal is normally accomplished with sealing gaskets applied between the caps and the open ends of the rollers. However, it has been noticed that workers tend to over-tighten the bolts that secure the caps to the open ends of the rollers, which over-compresses the sealing gaskets crushing them to the point of failure or to the point to cause premature failure, thus necessitating further improvement in the art.